I sold the couch/loveseat out of my '06 Cruiser for $100. Had immediate replies to the ad, and the 1st one to show up with the cash got it.
In your ad, be sure to show how much a NEW couch or dinette would cost someone if they bought it from a retailer. That can be a huge selling point...
There are lots of people out there that don't want to mess around building custom furniture, or driving around measuring "house" furniture to see if it fits. Being able to cheaply replace worn out RV furniture with better condition RV furniture is what they are looking for...